LOG_WRITER.md

LogWriter

LogWriter takes care of deciding where to log the messages.

Prebuilt LogWriters

By default Kermit provides default LogWriter for each platform

• CommonWriter - Uses println to send logs in Kotlin
• LogcatWriter - Uses LogCat to send logs in Android
• NSLogWriter - Uses NSLog to send logs in iOS
• ConsoleWriter - Uses console to log in JS

These can be created and passed into the Logger object during initialization

Logger.setLogWriters(listOf(LogcatWriter(), CommonWriter())

Custom LogWriter

If you want to have a custom implementation to send logs to your own server, or a 3rd party tool or simply because default implementation doesn't fit your need, then you would need to extend the LogWriter class and provide your own instance.

For a simple LogWriter you only need to implement the log method, which handles all logs of every Severity.

Simple implementation would look like below,

class YourCustomWriter : LogWriter() {

    override fun log(severity: Severity, message: String, tag: String, throwable: Throwable?) {
        // Handle logging here
    }
}

You can optionally override the severity convenience functions if desired.

override fun v(message: String, tag: String, throwable: Throwable?) {
    Log.v(tag, message, throwable)
}

isLoggable

Custom loggers may also override fun isLoggable(severity: Severity): Boolean. Kermit will check this value before logging to this LogWriter.

Simple example of that would be: If on your Android build, you have your own LogWriter and you want to handle logs only on debug build then you could do that using isLoggable

// Custom Implementation
class YourCustomWriter(private val shouldLog: Boolean) : LogWriter() {

    override fun isLoggable(severity: Severity): Boolean {
        return shouldLog
    }

    override fun log(severity: Severity, message: String, tag: String, throwable: Throwable?) {
        // Handle logging here
    }
}

// Usage 
val logWriter = YourCustomWriter(shouldLog = BuildConfig.DEBUG)
val logger = Logger(LoggerConfig.default.copy(logWriterList = listOf(logWriter)))